1. Field of the Invention
This invention relates to integrated circuit (IC) fabrication technology, and more particularly, to a position detector for use on a spin-drying machine employed in IC fabrication to detect whether the spin-drying machine has shifted in position during operation. In the event that the spin-drying machine shifts in position during operation, the position detector is capable of stopping operation of robot arms used to move wafers to and from the spin-drying machine so that the robot arms will not be damaged or crash into the wafers on the spin-drying machine.
2. Description of Related Art
One drawback to the foregoing spray/puddle development method, however, is that, during the spin-drying process, the spin-drying machine may shift in position due to its spinning motion. Conventionally, however, the spin-drying machine is unable to detect such a condition, and, as a result, the robot arm may be damaged or crash into the wafers on the spin-drying machine.